DUESSELDORF, March 29 (Reuters) - A far-reaching agreement between India’s Tata Steel and its Dutch unit could put at risk plans for a steel joint venture with Thyssenkrupp , the German group’s supervisory board vice chairman said.

Thyssenkrupp and Tata Steel last year announced plans to combine their European steel operations to create the continent’s second-largest player after ArcelorMittal, including up to 4,000 job cuts.

In February, Tata Steel guaranteed its Dutch division could continue to operate as an independent company within the planned joint venture with Thyssenkrupp, with control over its own profits and an independent supervisory board.

The deal has been criticised by German labour representatives who argue that the Dutch business will dodge responsibility in the new joint venture while the German sites would bear the brunt of the risks.

Talks to get the joint venture plan underway have been challenging from the start, with workers at both groups — with plants in Germany, Britain and the Netherlands — fighting for deals to protect jobs and sites in the volatile steel sector.

“Should the agreement for the Netherlands remain in place we will demand the same for us,” Markus Grolms, who also serves as trade union secretary at the IG Metall union, told Reuters. “But then a joint venture no longer makes sense because every unit would only act on its own.”

Grolms said he expected an investigation into all aspects and implications of the agreement.

Thyssenkrupp declined to comment.

In a document seen by Reuters, Tata Steel said it had agreed with Thyssenkrupp to make IJmuiden the R&D headquarters of the joint venture company, which will also be based in the Netherlands.

“At the moment, I am lacking the imagination for how this problem can be solved. Apparently, agreements have been made in the Netherlands already. The board will have to be able to explain that to us,” Grolms said.

Thyssenkrupp’s supervisory board will gather for an extraordinary meeting on April 12, with the steel joint venture, which was originally planned to be signed in the beginning of 2018, among the topics to be discussed. (Additional reporting by Christoph Steitz; Editing by Arno Schuetze and Elaine Hardcastle)